Effects Of EMS And Other Treatments On Embryogenesis Of Isolated Microspore In Non-heading Chinese Cabbage

Isolated microspore culture technology refers to the process of processing the microspore cells of the donor plant by foreign means under sterile conditions,so that the original gametophyte pathway is forcedly transformed into the sporophyte pathway,and the process of development and differentiation is formed into a complete plant.Because of its unparalleled superiority,microspore culture has been playing an important role in breeding since its discovery.However,because there are many factors that affect the embryogenic ability of the plant’s microspores,such as the genotype of the donor plant,the type of medium,etc.,how to optimize the microspore culture system to increase the rate of embryo emergence and the rate of embryoid plant regeneration has been many researchers Concerns.This study mainly explored the factors affecting the embryogenesis of isolated microspores in nonheading Chinese cabbage and the culture and ploidy identification of regenerated plantlets of microspores,aiming to improve the embryogenesis rate of isolated microspores in nonheading Chinese cabbage and optimize the technology of isolated microspore culture.Promote the progress of breeding research.The main findings are as follows:(1)Using 12 non-heading Chinese cabbages with different genotypes as experimental materials,the effects of genotypes on embryogenesis of non-heading Chinese cabbage were studied.The results showed that 6 varieties obtained embryoid bodies,and the embryogenesis rate was 50%.Among the emerged varieties,the highest emergence rate was ’NHCC-068’,with an average of 11.4 embryos/buds;’NHHCC-224’ emerged the rate is the lowest,but there are also 1.18 embryos/buds.(2)According to the situation of embryo emergence,select varieties with different embryo abilities to carry out experimental research.Choose ’NHCC-224’ and NHCC-068’ to explore the effect of ABA concentration on microspore embryogenesis;choose ’Kuai cai’,’NHCC-224’ and ’Jihong doll commercial species’ to explore the BR concentration on microspore The effect of embryogenesis;select ’Kuai cai’ and ’NHCC-068’ to explore the effect of MB concentration on microspore embryogenesis;Select ’K2’ to explore the different concentrations of EMS treatment at different times on microspores The impact of embryogenesis.The results show that ABA at a concentration of 0～1 mg/L can increase the germination rate of microspores.When the concentration is higher than 2 mg/L,it will inhibit embryogenesis;BR at a concentration of 0～16 mg/L can promote embryos occurred,but different genotypes had different optimal MB concentrations;MB of 0～10 n·mol/L can all improve embryogenesis ability,but above 12 n·mol/L will inhibit embryogenesis;0～1.2‰EMS concentration treatment for 10 minutes can promote non-heading Chinese cabbage embryogenesis,but when the treatment time is 20min,only 0.4‰ EMS significantly promotes embryogenesis,0.8‰ and 1.2‰ EMS will inhibit microspore embryos Generating ability.(3)The embryoid bodies obtained by culturing microspores of different varieties were used as experimental materials to study the effect of genotypes on the regeneration of microspore embryoid bodies of non-heading Chinese cabbage.The study found that ’NHCC224’ had the highest germination rate of 69.36%;’G112’ had the lowest seedling rate of 0%.(4)Use morphological identification and flow cytometric analysis to identify ploidy of the DH regenerated population plants.Observation found that with the increase of ploidy level,the growth of the plant increased,the leaves became larger,and the inflorescence became longer;the number of haploid flower buds was small and not full,without pollen.Ploidy identification of all regenerated plants revealed that there were both haploid,diploid tetraploid,and chimera.Among them,the natural double rate of ’NHCC-224’ is the highest at 77.3%;the natural double rate of ’NHCC-068’ is the lowest at 60.47%.